Automotive vehicles incorporate a variety of restraint systems to provide for the safety of occupants. For example, it is known in the vehicle art to provide various types of seat belts or restraint systems for restraining an occupant in his or her seat and for providing controlled deceleration of the occupant from an event such as a collision. Various types of seat belts and restraint systems have been used in automobiles, trucks, and other vehicles and are commonly known today.
Known seat belt systems typically used in commercially available production vehicles include a seat belt telltale that is visible to the driver. The seat belt telltale is illuminated in the event that a seat belt is not being used in 3-point seat belt systems for some time.
A commonly used telltale arrangement includes an electrical switch in the buckle that senses engagement between the tongue or latchplate and the buckle. This arrangement identifies the buckle status and, hence, seat belt usage. Non-compliance with seat belt usage results in a signal light being illuminated on or near the instrument cluster. This signaling is initiated when associated electrical information (e.g., voltage) is transmitted using a wiring harness attached to the buckle assembly and subsequently used (e.g., by a Restraints Control Module [an “RCM”]) to determine if the telltale should be illuminated. Examples of buckle switch systems may be found in U.S. Pat. Nos. 4,060,878, 4,163,128, 4,920,629, and 6,381,815.
An alternate method for sensing seat belt use compliance is an arrangement that is used to determine if the amount of extraction of webbing from the seat belt retractor is greater than a minimum amount that would indicate seat belt usage. This is commonly done using a mechanical device in the retractor which determines the number of revolutions of the retractor spool and hence the amount of webbing extracted. An example of this arrangement may be found in U.S. Pat. No. 4,866,223.
While the above-cited references provide certain advancement in the state of the art of systems for detecting and relaying information relative to seat belt use compliance, opportunities for improving such systems yet exist.